Near-surface permafrost degradation: How severe during the 21st century?

[1] A previously presented model on nearly complete near-surface permafrost degradation in the Arctic during the 21st century is critically reviewed. An alternative model with a more complete mathematical formulation of the physical processes acting in permafrost terrain is presented, which suggests that permafrost will mostly prevail in this century in areas north of 70 degrees N. Furthermore, permafrost will survive at depth in most areas between 60 degrees to 70 degrees N. Based on paleoclimatic data and in consequence of this study, it is suggested that scenarios calling for massive release of methane in the near future from degrading permafrost are questionable.